Abstract

This document describes the DISCOVER opcode, an experimental
extension to the Domain Name System (DNS) to use multicast queries
for resource discovery. This opcode was tested in experiments run
during 1995 and 1996 for the Topology Based Domain Search (TBDS)
project. This project is no longer active and there are no current
plans to restart it. TBDS was the first known use of multicast
transport for DNS. A client multicasts a DNS query using the
DISCOVER opcode and processes the multiple responses
that may result. This document defines a Historic Document
for the Internet community.